simpson



(No Model.) 3 Sheets-Sheet 2.

L. SIMPSON.

, KI-LN.

, No. 349,755. Patented Sept. 2 8, 1886.

l 3 Sheets-Sheet 3. L. SIMPSON.

(No Model.)

KILNr Patented sept. 28, 1886.

WWK-masas:

UNITED STATES PATENT OFFICE.

LENOX SIMPSON, OF BELLEVUE, ALLEGHENY COUNTY, PENNSYLVANIA.

KILN.

SPECIFICATION forming part of Lettr Patent NO. 349,755, dated September28, 1885.`

Application filed January 27, 1886. Serial No. 189,980. (No model.)

.To all whom it may concern:

Beit known that I, LENoX SIMPSON, a citizen of the United States,residing at Bellevue, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inKilns, of which the following is a clear, full, and exact description.

The object of my invention is to obtain a uniform heat in all portionsof the body operated upon.

The particular application of the invention i is to the burning ofbrick, tile, and other analogous articles, and the result aimed at is akiln of brick or tile equally burned, and consequently of uniform colorthroughout. I attain this object by constructing a kiln or furnaceprovided with a heating-chamber protected from all drafts andair-currents, and having a superposed combustion-chamber, all arrangedand operated substantially in the manner hereinafter set forth.

In the drawings, Figurel represents afront elevation of the furnace orkiln; Fig. 2, a longitudinal' section of same, and Fig. 3 a transversesect-ion.

Similar letters of reference indicate corre-l jected to an excessiveheat, (far more than that required for burning) while the brick, &c., atand near the top of the kiln, fromf lack of heat are never properlyhardened. Furthermore, the flame and products of combustion in passingupward seek to move in straight lines, and, notwithstanding the meanstaken for deileciing and diffusing the heat, those portions of the brickwhich lie between the arches must necessarily receive less heat thanthose immediately above lthe same. Even where the flames and products ofcombustion are conducted from external fire-places under the whole of aperforated kiln-floor, the result must in a lesser degree remain thesame, for the heat must be greatest at those points nearest the sourceof supply, and gradually lessen as the distance from same increases.

In the downdraftkiln the flames and produc-ts of combustion, afterleavingrthevtops of the supply-fines, move in as nearly as possiblestraight lines toward the openings in the loor connecting with thestack. f The top brick nearest the tlues will therefore receive thegreatest amount of heat, while those brick which lie near the center ofthe kiln and those near the door will receive less.

In a kiln heated by convection-i. e., a close kiln heated at thebottom-the heated air traverses the kiln in 4curvilinear currents,starting at those points where there is direct application of thetire,proceeding upward, and returning where thedirect application of theheat is least perceptible. The brick therefore will be burned. hardestand darkest immediately above the fire arches, less toward thetop, andleast near the bottom between the arches. Finally, it is obvious thatwhether a draft or current be up or down or circuitous, the heat mustalways be greatest near those points from which the drafts begin andleast at those points where the drafts fail to penetrate. In view ofthese facts, the desirability of dispensing altogether with drafts orcurrents suggested itself. The only means of accomplishing this istoapply the heat from above and confine the brick, tile, or analogousmaterial Within a chamber having closed sides and bottom, and protectedfrom the currents necessarily formed in the combustionchamber.

A is the furnace or kiln, whose heating or working chamber a is cut-offfrom all ingress of air from the sides and bottom. A door or archedopening. Ais provided through which the chamber is filled. This door ishermetically sealed rbefore the fires are lighted.

B is an arched chamber raised a sufficient distance above the level ofthe top of chamber ato allow ample-room for combustion. The object ofthis construction is to allow room for the passage of the flames andproducts of combustion, without said llames, Sto., impinging upon thecontents of chamber a.

C are the bridge-walls, from which extend vinwardly the deilectors c.Instead of the de- IOO iiectors c a floor, covering the space betweenand that occupied by the deflectors, may be used. This iioor would beprovided with oblique openings, which, while not preventing the downwardtransmission of heat through the air, would cut oft' all radiated andreflected heat. The object of the deflectors is to deflect thecentrifugal currents toward the center of the arch.

D are two fire-places situated at either end of the kiln, and connectedby throats or ues d with the combustion-chamber B.

In the bridge-walls C zigzag air-passages c are formed, which open, onthe one hand, into the external air, and, on the other, into thecombustion-ch amber B at the top of the bridgewalls. f By the foregoingmeans a current of hot air is induced and the products of combustion andsmoke consumed in chamber B.

E is the flue connecting with the stack.

Dampersf y 71, situated in flues d E, and airpassages cf regulate theheat within the combustionchamber. One or more peep -holes are left inthe walls of chamber a, near its top and above the tops of the bricks tobe burned,

r as shown at a.

It will be understood that the construction described is susceptible Lofgreat variation. Thus if gas or oil be used as fuel, the fire-places andair-fines would be dispensed with, and a square combustion-chamber mightbe substituted for the arched one described.

The essential feature of the invention is a heating or working chamberdevoid of drafts or currents and a superposed source of heatsupply.

The operation of the invention is as follows: The brick, tile, or othermaterial to be operated upon having been placed in position within thechamber a, the door of the chamber is closed and sealed and the fireslighted. The fires are kept low until the brick have had time to becomethoroughly dry. Afterward the res are increased until the top bricks areof a bright-red heat. It is obvious now that the heated air, beinglightest, will remain at t-he top, and that all the air in chamber awill be graduated in temperature from the top to the bottom. A portionof the heat from the top stratum of air will be transmitted to thestratum immediately beneath,and from that to the next lower stratum, andso on until the bottoni is reached. During this transmission the onlychange which takes place in the air within chamber a is its rarefaction,and this, being from above, cannot create a current. The bridge-wallsare of considerable thickness, and, in connection with-the constant flowof air through same p the damper g opened.

prevent any perceptible heat from being trans mitted from the iiues tothe heating-chamber. If the fire tends to become too hot, the dampers f7L are partially closed and, if necessary,

The effect of this is to.

reduce the heat in the combustion-chamber. If the combustionchamberappears to be cooling, "the dampers may be opened wide and thecombustion thereby increased. By observing the top brick through thepeep-hole and regulating the dampers in the foregoing manner the uppertier of brick may be kept at the desired bright-red heat for anindefinite period. Meanwhile the heat has been slowly transmitteddownward from one stratum of air to another, until finally the bottomtier of brick will also attain a bright-red heat. Vhen this point isreached, the whole body of brick will be of a uniform temperature. Thefires are now drawn and the brick allowed to cool. As the' coolingbegins at the top and proceeds downward, by properly regulating thedampers the process of heating may be exactly reversed. In this' wayevery brick may be made to hold its heat for an equal time, the top heating and cooling first, and the bottom heating and cooling last.

I do not broadly claim the use of an arched combustion-chamber, nor theuse of ahotcur* rent of air to complete the combustion, as thesefeatures are common to various kinds of furnaces. Nor do I claim,broadly, the application of the heat to the brick from the top of thefurnace downward, as this mode of applying the heat is common to alldowndraft-kilns; but

What I claim isl. The within-described method of burning brick, tile, oranalogous articles, which consist in conning same in a close chamberfree from drafts or currents, and heating from the top downward,substantially as and for the purpose described.

2. In a brick-kiln, the air-dues c', arranged inthe side walls, C,between the chamber aand fire-flues d, as and for the purpose described.

3. In a furnace for burning brick, tile, and analogous articles, thecombination, with the chambers a and B, of the deflectors c, as and forthe purposes set forth.

4. In a furnace for burning brick, tile, and analogous articles, thecombination, with the chamber a, of the arched com busticuchamber B, thetop of said arch being raised above the top of chamber a a distanceapproximately equal to the diameter of the circle of which the archforms apart, substantially as and for the purposes described.

5. In a furnace for burning brick, tile, and analogous articles, thecombination of the heating-chamber a, the combustion-chamber B,deflectors c, fire-places D, flues d E, and air-passages c.substantially as and for the purposes described.

6. In a brick-kiln, the chamber a, provided with one or more peep-holesat the top, and combined with dampers f g h, arranged as shown, wherebythe heat may be regulated by observing the top bricks and operating thedampers, as set forth.

LENOX SIMPSON.

Witnesses;

W. l). THOMAS, JNO. A. KURTZ.

IOC'

I IO

